The U.S. Pat. No. 5,494,290 discloses a golf putter handle which is provided with a laser member, a through hole, and a control button. The through hole is provided respectively in the inside thereof and in the outside thereof with a reflector under which a round reflector is disposed. The handle is provided with a battery. In operation, when the control button is pressed, an aiming line is projected on the head such that the aiming line is perpendicular to the ball striking surface of the head. Such an aiming device as described above must be purchased along with a golf putter and is rather expensive.
The U.S. Pat. No. 5,611,739 discloses a putter which is provided in a head thereof with an aiming device capable of emitting an aiming line perpendicular to the ball-striking surface. The aiming device is sold separately and can be detachably fastened with the putter. The drawback of the aiming device is that it is visible to a golfer using the putter. In addition, the aiming device gives an added weight to the putter head.
The U.S. Pat. No. 5,725,440 discloses a putter which is provided in the grip thereof with a cavity in which a laser pen is disposed. The putter shaft is provided in the bottom end thereof with a reflector capable of reflecting light at right angle so as to form an aiming line. The putter is expensive.
The U.S. Pat. No. 5,707,296 discloses a putter head which is provided at two ends thereof with a laser member. The two laser members emit two aiming lines parallel to each other. The putter is expensive and can not be used in a tournament.
The U.S. Pat. Nos. 5,464,221 and 5,464,222 disclose respectively a putter which is provided in the juncture of the head thereof and the shaft thereof with a laser member for emitting an aiming line. The putter is not cost-effective and is used for practice only. In addition, the aiming line emitted by the laser member is fuzzy.